Devices such as firewalls are sometimes used to prevent users, such as employees of a company, from accessing resources to which they are not authorized. As an example, access to a specific website or to a class of websites may be prohibited for all users. Access can also be granted in a more granular level, such as by permitting some users or groups of users to access a resource, while prohibiting access for other users/groups. Unfortunately, enforcing granular polices can be difficult, particularly as the number and variety of types of devices present in an enterprise network continue to increase.